Glasgow three-piece Holy Mountain know how to rock. This might seem a simple duty from a rock band, but it so very rarely happens, especially with this kind of intensity and compulsive riffage expertise. With Andy McGlone on guitar, Pete Flett on drums and Allan Stewart on bass, the premise and the practice are simple: stripped-down riffs, the odd tortured vocal, and plenty of riff time changes, double-backs, switches and longeurs. The first track on this debut album, the propulsive Gunner, reminds me of Sky Valley-era Kyuss (I can hardly think of higher compliment); elsewhere there are echoes of, inevitably, Black Sabbath and even the grime of the late-lamented Iron Monkey. The live arena will be Holy Mountain's true domain, but for a first album of explosive zero-gravity riffage, this is immense.